1. Field of the Invention
The present invention relates to a mobile vehicle (mobile object) such as a two-wheeled vehicle having a front wheel and a rear wheel.
2. Description of the Related Art
In a mobile vehicle, for example a motorcycle, having a front wheel and a rear wheel arranged spaced apart from each other in the longitudinal direction of the vehicle body, the front wheel usually serves as a steered wheel.
Further, a motorcycle in which the rear wheel is made steerable, in addition to the front wheel, is also known as seen, for example, in Japanese Patent Application Laid-Open No. 2008-260316 (hereinafter, referred to as “Patent Literature 1”). In the motorcycle of this Patent Literature 1, the rear wheel is steered as appropriate, in accordance with the traveling conditions, to improve the turning performance, for example, of the vehicle.
In a motorcycle of this type, the steering axis of the front wheel (rotational axis of steering of the front wheel) is generally arranged such that the point of intersection of the steering axis and the ground surface with which the wheels come into contact lies in front of the ground contact point of the front wheel (i.e. such that the trail becomes positive).